Technical Field
The present invention relates to detecting defects in ferromagnetic materials and, more particularly, to systems that facilitate visualizing detected defects.
Related Art
Ferromagnetic materials, such as iron, nickel, steel and other materials, are used to make many items, such as pipes, beams and ocean vessel hulls. Defects, which may develop in the ferromagnetic materials over time, can cause problems. Prior art systems can provide location information about a defect. However, actually locating a physical portion of a ferromagnetic material, such as a buried pipe, to gain physical access to the portion that contains the defect remains very difficult.
As used herein, “ferromagnetic material” includes both ferromagnetic and ferrimagnetic material. In many cases, these materials are subject to corrosion and/or erosion. As used herein, corrosion means loss of material as a result of chemical reaction, most commonly oxidation. As used herein, erosion means loss of material as a result of a mechanical process, such as abrasion. For example, sand produced in an oil or gas well can abrade the inside of a pipeline carrying oil or gas from the well. Material loss due to corrosion and/or erosion is collectively referred to herein as a “defect.” As used herein, the term defect also includes a crack, or a void or inclusion of foreign material, such as might occur during manufacture or later. If allowed to occur beyond a critical point, corrosion, erosion or another defect may compromise structural integrity of an item, possibly resulting in a catastrophic failure, such as an oil spill, building collapse or ship sinking.
Magnetometry-based systems and method for detecting defects in ferromagnetic material are known, as exemplified in U.S. Pat. No. 9,651,471 ('471), issued May 16, 2017, titled “System and Method of Measuring Defects in Ferromagnetic Materials,” U.S. Pat. No. 9,651,472 ('472), issued May 16, 2017, titled “System and Method of Measuring Defects in Ferromagnetic Materials,” U.S. patent application Ser. No. 15/197,699 ('699), filed Jun. 29, 2016, titled “System and Method for Characterizing Ferromagnetic Material,” and U.S. patent application Ser. No. 15/653,036 ('036), filed Jul. 18, 2017, titled “System and Method for Characterizing Ferromagnetic Material,” the entire contents of each of which are hereby incorporated by reference herein, for all purposes.
However, pipe inspection, repair and/or replacement, particularly in a large, complex facility, such as a processing plant, requires an ability to locate both a detection device and a defect the detection device finds. Geolocation, i.e., stating where in the facility the device or defect is, has been historically done by using sector and pipe identifiers from drawings of the facility. While useful when looking at data in a control center, this information is cumbersome in the actual facility, where many of these reference location identifiers are not present. Furthermore, in some situations, precise location of the defect is a critical piece of knowledge in both diagnosing the defect and selecting next steps to be performed.
When a magnetometry-based detector is used, an output of the detector gives indications of the defect location, but locating this position directly on the pipe can be difficult. In the case of a scanning magnetometry system, one needs to recreate the scan locations to find the precise location of the defect. For permanently-mounted magnetometry systems, the defect is below the sensor area and, therefore, difficult to precisely locate, if the magnetometry sensor is removed, which is typically done for further analysis, inspection or repair of the defect.
Often, industrial pipes are coated with protective layers and/or layers of insulation with cladding over the insulation. It is very difficult to translate any location points that may be marked on the insulation, or its cladding, down to the pipe itself, because removing the cladding, insulation and pipe coatings destroys the reference points. Since pipe defects tend to be internal to the pipe, there is no external visual clue as to the defect location, even when all of the pipe coverings have been removed.
Thus, although prior art systems can provide location information about a defect, actually locating a physical portion of a ferromagnetic material, such as a buried pipe, to gain physical access to the portion that contains the defect remains very difficult.